In high capacity mobile radiotelephone communication systems, a plurality of base stations, also referred to as cell sites, are arranged so that each cell site covers a respective geographical area called a cell. These cells are grouped together to provide a wide area system coverage. Typically, each such cell site contains a pair of transmitter-receivers with a control that redirects traffic between cells to follow subscriber movement within a certain geographical coverage area. These systems are formed into a regional or nationwide network of telephone switching offices that link the mobile subscriber to the land based telephone network.
Because of a growing mobile radiotelephone customer base, mobile telephone service providers are faced with an increased demand for a variety of new and improved mobile services, such as for example, mobile data services. It is well known that mobile channel impairments contain regularly occurring signal level drops, and long interval degradations resulting from movements of the mobile transceiver within a cell along with interruptions from system signaling events termed blank and burst, where normal audio transmission is suspended for a short period to support system data management. Moreover, the topography of the terrain during such movements of the mobile station, as well as travel in high noise areas, can result in significant variation in transmission quality and/or reception of voice and data. Also, at the boundary of a cell in the hand-off range, i.e., when a moving mobile station travels out of one cell into a contiguous neighboring cell, a signal-to-noise ratio that may be marginally acceptable for voice service will often lead to errors during data transmission and/or reception. Typically, data products are not too tolerant of high error rates normally encountered with a voice grade of mobile radio telephone service because of the lack of interpretative ability found in normal conventional voice communications. Therefore, there exists a need for a mobile date telephone of a type capable of supporting high quality robust data transfer over the mobile channel air interface.